   require 'find'
    require 'MD5'

    files = {}

    Find.find(".") do |f|
        Find.prune if f =~ /\.svn/

        if File.file?(f)
            md5 = MD5.new(File.open(f, 'rb').read).hexdigest
            # puts "#{md5}: #{f}"

            if files[md5].nil?
                files[md5] = [f]
            else
                files[md5] << f
            end
        end

        # ruby -r md5 -e "puts MD5.new(File.open('filename', 'rb').read).hexdigest"
    end

    files.each { |md5, filelist|
        if filelist.size > 1
            # puts md5
            filelist.each { |filename|
                puts filename
            }
            puts
        end
    }

